91 research outputs found
Measuring the Food Environment: A Systematic Technique for Characterizing Food Stores Using Display Counts
Marketing research has documented the influence of in-store characteristics—such as the number and placement of display stands—on consumer purchases of a product. However, little information exists on this topic for key foods of interest to those studying the influence of environmental changes on dietary behavior. This study demonstrates a method for characterizing the food environment by measuring the number of separate displays of fruits, vegetables, and energy-dense snack foods (including chips, candies, and sodas) and their proximity to cash registers in different store types. Observations in New Orleans stores (N = 172) in 2007 and 2008 revealed significantly more displays of energy-dense snacks than of fruits and vegetables within all store types, especially supermarkets. Moreover, supermarkets had an average of 20 displays of energy-dense snacks within 1 meter of their cash registers, yet none of them had even a single display of fruits or vegetables near their cash registers. Measures of the number of separate display stands of key foods and their proximity to a cash register can be used by researchers to better characterize food stores and by policymakers to address improvements to the food environment
Structure - Activity Relationships in the Antiinflammatory Steroids: A Pattern Recognition Approach
A pattern recognition technique has been used to determine
structure-activity relationships for antiinflammatory steroids. Expe.:.
rimental results using the human vasoconstrictor test of McKenzie
and Stoughton and the rat granuloma cotton pellet method of
Meier were correlated with the various substructural descriptors.
Steroids were classified into two categories according to potency
and a pattern recognition method was applied to determine their
relative ranking. The resulting structure-activity relationships
obtained and the relative contributions of the various structural
variables for both bioassays are discussed. A synergistic effect
was predicted to be in operation between certain pairs of substituents
Dihydropyridine Isomerism in the Chemical Delivery System Series
A theoretical study was performed for three structured isomers of the dihydropyridine-targetor btised chemical delivery systems of estradiol euid azidothymine. The relative thermodynamic stabilities reflected by the calculated heats of formation (AHf) indicated, in good agreement with avedlable experimental evidence, preferential formation of the 1,4-dihydropyridine isomers as a result of thermodynamic product control. The increased relative stability of the 1,4-isomers, as compared to the 1,2-and 1,6-dihydropyridine, is explained by favorable electronic interactions (hyperconjugation, homoarom- aticily) existent in these derivatives
O fra Bernardinu Splićaninu, priređivaču prvog izdanja hrvatskog lekcionara, ponovo!
The use of miniaturised isotachophoresis to allow the simultaneous determination of two inorganic selenium species has been investigated using a poly(methyl methacrylate) chip with a 44-mm-long, 200-μm-wide, 300-μm-deep separation channel. The miniaturised device included an integrated on-column, dual-electrode conductivity detector and was used in conjunction with a hydrodynamic fluid transport system. A simple electrolyte system has been developed which allowed the separation of selenium(IV) and selenium(VI) species to be made in under 210 s. The limits of detection were calculated to be 0.52 mg L−1 for selenium(IV) and 0.65 mg L−1 for selenium(VI). The method allowed the separation of the selenium species from a range of common anions including fluoride, nitrate, nitrite, phosphate, sulfate and sulfite
Catalytic mechanism of alpha-phosphate attack in dUTPase is revealed by X-ray crystallographic snapshots of distinct intermediates, 31P-NMR spectroscopy and reaction path modelling.
Enzymatic synthesis and hydrolysis of nucleoside phosphate compounds play a key role in various biological pathways, like signal transduction, DNA synthesis and metabolism. Although these processes have been studied extensively, numerous key issues regarding the chemical pathway and atomic movements remain open for many enzymatic reactions. Here, using the Mason-Pfizer monkey retrovirus dUTPase, we study the dUTPase-catalyzed hydrolysis of dUTP, an incorrect DNA building block, to elaborate the mechanistic details at high resolution. Combining mass spectrometry analysis of the dUTPase-catalyzed reaction carried out in and quantum mechanics/molecular mechanics (QM/MM) simulation, we show that the nucleophilic attack occurs at the alpha-phosphate site. Phosphorus-31 NMR spectroscopy (31P-NMR) analysis confirms the site of attack and shows the capability of dUTPase to cleave the dUTP analogue alpha,beta-imido-dUTP, containing the imido linkage usually regarded to be non-hydrolyzable. We present numerous X-ray crystal structures of distinct dUTPase and nucleoside phosphate complexes, which report on the progress of the chemical reaction along the reaction coordinate. The presently used combination of diverse structural methods reveals details of the nucleophilic attack and identifies a novel enzyme-product complex structure
Barriers to remember: brain-targeting chemical delivery systems and Alzheimer's disease
Brain-targeted chemical delivery systems (CDSs) represent rational drug design attempts not only to deliver but also to target drugs to their site of action. Using a sequential metabolism approach, the special bidirectional properties of the blood-brain barrier can be exploited to smuggle the precursors of therapeutic compounds across the barrier and lock them inside the brain ready for sustained release of the active drugs. Many potential therapeutic applications can be envisioned for such CDSs; here, the potential of brain-targeted estradiol for the prevention and treatment of Alzheimer's disease is reviewed in detail
Drug targeting via retrometabolic approaches
Retrometabolic approaches incorporate targeting and metabolic considerations into the drug design process and represent a novel, systematic methodology for the design of safe, localized compounds. Two major design concepts aimed to increase the therapeutic index of drugs were developed.
Chemical delivery systems allow targeting of active biological molecules to specific target sites or organs, based on predictable enzymatic activation.
Soft drug approaches are used to design new drugs by building in the molecule, in addition to the activity, the most desired way in which the molecule is to be deactivated and detoxified subsequent to exerting its biological effects. Many examples are provided; related computer programs are also briefly discussed
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